Tuning of Large Sorts using SYNCSORT

dhok_ks · New User Joined: 09 Jun 2006 Posts: 1

I want to reduce run the elapsed time as well as the CPU time for the sort step.There are two instances:-

1.Here the input file is of VB and the LRECL is more than 30000 bytes.Also the file has 6 million records.I need to remove the duplicates from this file.This step runs for 4 hours and costs around $70.Please suggest any tuning for this.

2.There are two files which have combined of 88 million records and the record length is 3625.This step runs for 6 hours and costs $60.Please suggest a way for tuning this.

Note:- The estimated cost is seen in the JESYSMSG. I tried to use the VSCORET parm on the EXEC of the sort and the FILSZ parameter in the sort card bu there is not much reduction in the elapsed time.CPU time as well as the cost.

I am using SYNCSORT.

Regards,

Kaustubh

William Thompson · Posted: Wed Jan 03, 2007 2:24 pm

raak · Posted: Thu Jan 04, 2007 12:02 pm

hi thompson,

In our system also, we have the problem of Extended batch window due to high elapsed time from big sort jobs. But In my system, this PARASORT and MAXSORT is not present.
Is there any other way in which the tape files can be sorted in a much faster way than the usual sort?

William Thompson · Posted: Thu Jan 04, 2007 7:16 pm

Do you use Syncsort?
What version?
Do you have the Manual?

raak · Posted: Thu Jan 04, 2007 7:50 pm

yes Thompson,

we use SYNCSORT. Version is shown as 3, release 7.

I dont have the manual.

UmeySan · Posted: Fri Jan 05, 2007 3:10 pm

Hi !

A nearly same situation i solved by changing VSCORE and VSCORET to a adaquate size.

Also eliminating not nessesary sort-statements like SUM FIELDS=NONE
This option will load some internal routins although they are not used.

You wrote, your's sorting tape files. Can you load them on DASD first and then do the sort ??? Alloc them on real fast DASD, no multivolume, if possible same special reserved disks, allocations whith a minimum of extents, means mostly full primary allocation.

Also REGION=0M ???

Which JobClass, use a clas with high performance.

Have a look also at the DynAlloc-Parms of your Sort-Installation.
Don't specify Sort-Wk's in JCL.

//STEP02 EXEC PGM=SORT
//SYSOUT DD SYSOUT=*
//*
//$ORTPARM DD DSN=IER1337.MIA01250.SORTSPLT(SORTPARM),
// DISP=SHR

--> $ORTPARM = VSCORE=5M / VSCORET=30M

Regards, Umeysan

raak · Posted: Fri Jan 05, 2007 4:23 pm

Hi UmeyScan

It is not possible to use a DASD in my case. I have so many Tape files and all these contains records in the count of millions. creating large DASD files for all these TAPES just to do the sort is not possible.

Can u provide me some other efficient way in which Tape files can be sorted as they are without putting in to a DASD.

UmeySan · Posted: Fri Jan 05, 2007 4:43 pm

Hi raak !

Does this eventually mean, that you have more than one sortin.
I mean somthing like sortin01 on tape sortin02 on tape and so on ???

If so, sorry, you have to life with a hudghe elapsed time.

Perhaps your shop could send a message to syncsort for some help
of a specialist over there.

Regards, UmeySan